GENERAL CHEMISTRY REVIEWER (EXIT EXAM)

A solution contains 0.100 M sodium nitrate (NaNO3) and 0.200 M MgCl2. Find the ionic strength of the solution.

0.700 M

In the formula for determining the ionic strength, what does Z stand for?

charge

Which of the following equations represents a charge balance equation for a saturated solution of Ag₃AsO₄?

[Ag⁺] + [H⁺] = 3[AsO₄^3-] + 2[HAsO₄^2-] + [H2AsO₄^-] + [OH^-]

Analysis of a compound showed that it contained 76.0 % fluorine atoms and 24.0 % carbon atoms by mass. What is its empirical formula?

CF₂

A 3.903 g sample of a hydrocarbon is burned in an excess of dioxygen, producing 7.31177 g CO2 and 4.488 g H2O. What is the empirical formula of the hydrocarbon?

CH₃

Which substance would produce 2 mol of particles per mole of solute when dissolved in water?

NH₄CH₃COO

In the cell notation: Zn(s) I Zn+2 (aq) Il Cu+2 (aq) I Cu (s), which species acts as the oxidizing agent?

Cu⁺² (aq)

A compound is found to contain 27.3 grams of carbon, 4.55 grams of hydrogen and 36.4 grams of oxygen. The molecular weight is found to be 90.0. What is its molecular formula?

C₃H₆O₃

Calculate the mass deficiency in g/mol of Zinc-64 (actual mass = 63.9291 amu).

Do not include units in the answer box.

0.6002

Which of the following statements concerning nuclear bombardment and transmutation is/are correct?

3 only

A nuclear _____ is a self-sustaining series of nuclear fissions caused by the absorption of neutrons released from previous nuclear fissions.

chain reaction

Which of the following statements concerning radioactive decay is/are correct?

1 and 2

What is the standard enthalpy change for the combustion of liquid cyclopentane, C₅H₁₀?

2C₅H₁₀(I) + 15O₂(g) -+ 10CO₂(g) + 10H₂O(I)

Substance ΔΗ°_f (kJ/mol)

C5H10(1) -105.6

CO2(g) -393.5

H2O(I) -285.8

-6581.8 kJ

Reformulated gasolines

contain oxygenated compounds.

Which petroleum fractions can be used to make diesel fuel?

kerosene and fuel oil

Which of the following equations represents a charge balance equation for a saturated solution of Ag₃ASO₄?

[Ag⁺]+ [H⁺] = 3[AsO₄^3-] + 2[HASO₄^2-] + [H2AsO4^-]+[OH^-]

Balance the following electrochemical reaction in acid:

MnO₄^- (aq) + Zr(s) ←→ Mn²⁺(aq) + Zr²⁺(aq)

A cell consists of a magnesium electrode immersed in a solution of magnesium chloride and a silver electrode immersed in a solution of silver nitrate. The two half-cells are connected by means of a salt bridge. It is possible to increase the voltage of the cell by

decreasing the concentration of Mg²⁺ and increasing the concentration of Ag⁺.

Cathodic protection results when

iron is attached to a more active metal.

Which of the following statements is true concerning half-cell I as the voltaic cell shown below discharges?

[Zn²⁺] increases with time, and [CI^-] increases with time.

Which of the following is not correct for a typical, battery-powered electrical circuit?

the salt bridge equalizes gas pressure between the anode and cathode half-cells

Write the empirical formula for a carbohydrate.

(CH2O)n

One step in the isolation of pure rhodium metal (Rh) is the precipitation of rhodium(III) hydroxide from a solution containing rhodium(III) sulfate according to the following balanced chemical equation:

Rhz(SO4)3(aq) + 6NaOH(aq) -> 2Rh(OH)3(s) + 3NazSO4(aq)

If the reaction of 0.500 g of rhodium(III) sulfate with excess sodium hydroxide produces 0.330 g of rhodium(III)

hydroxide, what is the percent yield?

105 %

Balance the following equation with the smallest whole number coefficients. Choose the answer that is the sum of

the coefficients in the balanced equation. Do not forget coefficients of "one".

Al(s) + HCl(aq) —> H2(g) + AlCl3(aq)

13

When a 100.0 mL portion of a solution containing 0.500 g of AgNO 3 is mixed with 100.0 mL of a solution containing 0.300 g of K₂Cr₂O₄, a bright red precipitate of Ag₂CrO₄ forms. Assuming that the solubility of Ag₂CrO₄ is negligible,

calculate the mass of the precipitate.

0.4882 g

The solubility of salt A in 100 mg of water is 25 grams at 25C. A solution is prepared by adding 30 milligrams of salt A in

100 grams of water at 25C. The resulting solution after mixing is a/an

unsaturated

When 2.750 grams of Pb3O4 is strongly heated, it decomposes and produces 0.0640 gram oxygen gas and 2.686 grams of a second oxide. What is the empirical formula of this second oxide?

PbO

Blue light in the visible region has a longer wavelength than ___.

X-rays

A nucleus located to the left of the band of stability is expected to undergo what type of nuclear decay?

electron emission

How many Na⁺ ions are contained in 5.43 g of Na₃PO₄?

5.98 × 10²²

In a neutral polyprotic acid, the value of Ka2 will be ____

the value of Ka1 because ____.

smaller than; it is more difficult to remove a hydrogen ion from an anion than from a neutral molecule

A petroleum fraction contains

a mixture of hydrocarbons

The process of fractional distillation is used to

partially separate the many components of a complex mixture.

Which of these pollutants are associated with gasoline and its combustion?

all of these choices

What assumption must be true for radiocarbon (¹⁴C) dating to be useful?

A constant concentration of ¹⁴C is maintained in living plants and animals through equilibration with atmospheric levels of ¹⁴C.

Which of the following statements concerning radiation is/are correct?

1. An argon filled Geiger counter tube cannot detect neutron radiation.

2. Radiation only causes damage to biological materials.

3. The greater relative biological effectiveness of alpha radiation compared to neutron radiation means alpha radiation is more destructive to human tissue.

1 and 3

Which of the following statements regarding a fission based nuclear reactor is not correct?

The uranium dioxide fuel pellets used in a U.S. light-water reactor are made up mostly of the U-235 isotope.

Which of the following particles cannot be accelerated to high speeds in a particle accelerator or cyclotron?

neutrons

What is the frequency of an IR photon with a wavelength of 1.2 X 10^-3 cm? c = 3.00 X 10⁸ m/s.

2.5E13 Hz

A meat preservation technique requires sodium nitrite. The preservative is prepared by streaming NO(g) and O₂(g) through Na₂CO₃(aq). What is the percent yield for this reaction if the addition of 12.73 g of NO(g), 16.49 g of O₂(g),

and 35.82 g of Na₂CO₃(aq) result in the formation of 16.81 g of NaNO₂.

NO(g) + O₂(g) + Na₂CO₃(aq)-+ NaNO₂(aq) + CO₂(g)

57.43

Styrene's empirical formula is CH. When it is heated to 200C, it is converted into a polymer, polystyrene, which has excellent insulating properties. What mass of styrene contains 1.77E21 molecules of styrene? The molar mass of styrene is 104 g/mol.

0.305 g

What is the balanced oxidation half-reaction provided below?

Zn(s) + 2H⁺(aq) —> Zn²⁺(aq) + H₂(g)

Zn(s) -> Zn²⁺(aq) + 2e^-

Calculate for the cell potential generated from concentration cells of Fe³⁺(aq)/Fe(s) with concentrations of 1.00 M and 0.100 M at 20 degrees Celsius.

0.0194 V

has zinc can as the anode; a graphite rod in the center, surrounded by a paste of manganese dioxide, ammonium and zinc chlorides, and carbon black, is the cathode.

Leclanche dry cell

Reduction occurs at the anode of a Galvanic cell.

False

This illustration depicts which of the following?

photomultiplier tube

What do you call a natural polymer made up of 2 up to 50 amino acids?

peptide

Which of the following base pairs is possible in RNA?

None of the above

Which of the following is a synthetic polymer?

Polystyrene

Metals not only served as indicator electrodes for their own cations but also respond to the activities of anions that form sparingly soluble precipitates or stable complexes with such cations

Electrode of the second kind

Used to minimize the liquid junction potential

Salt bridge

Which of the following is the ultimate reference electrode

SHE

Prior to 1975, the most common octane enhancer used in gasoline in the United States was

tetraethyllead.

Which of the following classes of organic compound is not a component of crude oil?

alcohols

Which of the following statements is/are true in chemical reactions?

i. The activation energy of an exothermic reaction is lower than an endothermic reaction.

ii. An exothermic reaction will have a positive 4Hºxn while an endothermic reaction will have negative AH^o_rxn

iii. An exothermic reaction will result to a hotter surroundings while an endothermic reaction will result to a colder

surroundings.

I. and II.

Which of the following measurements involves electrolysis?

A stripping analysis of uranium in water

Which of the following cells involves a spontaneous reaction?

Cell 1: Ecell = 0.545 V

Which of the following statements is/are true of solid propellants used as rocket fuel?

1. Rockets using solid propellants are less controllable than liquid-propellant rockets.

2. Solid propellants are simple and relatively inexpensive than liquid propellants.

3. Mixture of ammonium perchlorate and aluminum powder bonded together with a polymer can be used as a solid propellant.

1, 2, and 3

If a polymer is said to be thermoplastic, this means that it

will become fluid repeatedly upon heating.

A sample of crude oil undergoes fractional distillation with ____ being collected at the bottom of the distillation tower, and _____ at the top

High molecular weight fractions; methane and ethylene